Cadillac Powertrain Control Module (PCM) Tuning Discussion, Swapping Northstar for LS Engine in Cadillac Engine Technical Discussion; I realize that most people don't want Cadillacs for hot rods and all that, but at the same time, I ...

Swapping Northstar for LS Engine

I realize that most people don't want Cadillacs for hot rods and all that, but at the same time, I see no point in having such a sweet ride, all that technology, and all that power into a car that only old people generally can afford, and then other people just keeping them mainly stock because very few people make performance parts for them. I have a '94 Eldorado 4.6 that I am absolutely in love with, and even more so do I love hearing people talk shit about them in comparison to their little 4 cyl rice burners as it clearly shows intimidation. I'm not an ******* with it.....ok maybe a little bit, but not too much. My dilemma is this: why couldn't a Cadillac, which generally speaking you can get a little older one with the same specs and style as some new ones, relatively inexpensively, be modified to accept a larger crate engine, such as a 350 LS1/LS2, which would rocket the horsepower, without sacrificing the luxury of driving a good old Caddy? I was really excited to get to work on suping it up, with air intakes, exhaust, perhaps a universal turbo, and all this stuff, but I usually find that these motors are pretty much maxed out from the factory. Therefore, trade the motor, keep the body, and mod an engine they make mods for. I would like to drop an LS2, 400 hp, 364 6.0 Corvette engine in mine, which I could do within my price range. The hidden fees like the alternators and ecm and all that isn't really unnegotiatable either. But will it work? Can I change this car over to accept that type of motor, with ETC and all that? Will it fit? Welding and chassis work is not a problem, but this car will see some drag time, and I don't want to stick with the 6 second times forever. It's got potential to be mean and I would like to know how to harness this. If this won't work, does anyone know of another engine I can drop in it? Any ideas, answers, and opinions will be much appreciated. Thanks a lot, and maybe I won't feel like the only guy in the world that's ever considered this.

Rick

P.s. If you're one of those people who think this is blasphemy for doing this to a Cadillac or think I'm just a moron for not buying a little Mustang or something, (not trying to be rude), but please don't even bother replying to this thread, wasting my time, and making both our blood pressures rise. It's not healthy and I don't need another person to try and change my mind as it has failed to do so yet. Thanks again.

Re: Swapping Northstar for LS Engine

Uh...mainly because they're FWD cars that were built to accept the range of Northstar FWD engines, and some of the older 4.5L/4.9L's. A typical workhorse 350 or otherwise small block V8 is mostly setup for RWD applications, such as trucks and certain older cars.

So, it essentially just comes down to the FWD vs. RWD issue. Currently, there ARE some FWD GM vehicles with the LS-series 5.3L (Impala & Monte Carlo SS and Grand Prix GXP), and given some basic similarities between front end components in those cars and the typical 90's Cadillac, that could be a possible swap.

But for downright drag racing and such, like you bring up, that would be mainly for RWD and any one of a number of V8's...and can be done, but it would require fabbing up a completely new understructure, suspension bits, etc.

Hope that answers something...a FWD Northstar V8 Cadillac can be made to do some pretty incredible things from a racing aspect, but are still quite complex and not really intended for that sort of thing. And no typical pushrod GM V8 will really go in that easily.

If you want to pick up say, an Eldo, and then maybe a Camaro or something and figure out a way to meld the two into one...then you might have something...but the time and money just wouldn't be worth it.

Re: Swapping Northstar for LS Engine

Cruiser,
Thanks very much for the reply, the fabrication aspects of this would not be a hinderance to me as this would be a fun learning project which is half the enjoyment for me with this car. You mentioned the setup in an LS1 V8 for GTOs and such but what major changes would be needed to use that motor in the cadillac? Passive struts, fender cutting? It just seems such a waste to "settle" with anything with this car as they have so much potential. But let me ask you this, if upgrading that way is a bad idea, then what would YOU personally advise now that you know I want to stay with that car if at all possible without sacrificing much. Also, what is the limit and when would a wild eyed mini-gearhead like me be pushing the envelope with the Cadillac skeleton? Thanks so much for all the help.

Re: Swapping Northstar for LS Engine

I think I have given up on being sacreligous on the idea of swapping a non branded engine into a car. But honestly, if you can't get what you want from what you have, and you can take advanatage of modern technology do it.

But I still get ticked off at people putting Chevy engines in Pontiacs. I would never do. But my Cadillac CAME with a Chevy engine, so I don't have a problem putting a LS1 in mine, which I hope to do soon.

Re: Swapping Northstar for LS Engine

N0DIH,
That's sounds good, that thing should run great. And I feel the exact same way that you do about the Chevy/Pontiac thing though. The Brougham is RWD right? I have been looking into an LS4 which I believe is made for transverse applications where mine is FWD. Is there anything else that you are going to do to it? I'd like to know where you stand and hear what you do as you begin that project. By the way, three questions: What are some major differences in performance and whatnot with the DOHC to SOHC setup from the Northstar to the LS4? Can the cylinders be bored out in a 4.6L Northstar, I don't mean should I, I mean can it be done? If so, just buy a bigger sleeve, bigger pistons etc etc? And can the aluminum pistons in a Northstar be replaced with cast iron ones? Thanks everyone.

Re: Swapping Northstar for LS Engine

Honestly, if you could get a LS4 5.3L out of a Impala SS or GXP Grand Prix, engine/trans/engine controller, you would have a rocket. And the mods you can do to that motor far outshine anything the N* can ever dish out.

The beauty of the 5.3L LS4 is the only difference between the 5.3L and the 6.0L is crankshaft. So you can easily make the LS4 a LQ9 with only a crank, heads and cam change and you are close to 400 hp. And with an aftermarket cam and some porting, it makes for an easy 450-500 hp engine with excellent street manners. You can easily do PCM tuning on the LS engines, but virtually nothing exists for the N* in tuning. So no matter what mods you do, the engine will never run right and always be limited.

You CAN mod the N*, but I would be willing to bet the bore is probably limited to only a mm more than it is now, if even that. The cams would have to be custom reground, as no aftermarket cams out there, just regrinds (a common Cadillac problem), no PCM tuning, so it limits you to exhaust, intake, cam regrinds, and and porting mods. Which can gain a lot, but without the PCM tuning, it may not bring full potential, but it likely get you into a problem of check engine lights when the BLM values start to stray and you can get them back by tweaking the right values.

Re: Swapping Northstar for LS Engine

Not saying it couldn't be done, but it'd be a TON of work. I've thought about this kind of swap a lot since getting my 95 Eldo. The biggest problem you would have is locating the driveline, and the exhaust. There is a small "tunnel" in these cars to rout the factory exhaust, but that would have to become the driveshaft tunnel. Then....there's no place to route the exhaust as there's not much of a frame. You'd almost have to fab up a full frame first, then figure out where to put everything. If you have any more ideas, PM me, and we can discuss it.

Re: Swapping Northstar for LS Engine

Seeing how much room the 94-96 Deville has underhood, I think a LS swap should be fairly easy. The thing is trans bolt pattern (adapter) and then a front (left) truck exhaust manifold and a GTO back (right) side manifold and run dual pipes out back, maybe a large 3" or 3.25" single pipe out to the back and dual mufflers (think of it as a tall x-pipe....).

Swap a LS6 intake on installed backwards if you can so the TB is over the trans. Use a Corvette PCM/BCM and adapt the factory electronics to the LS1 using this PCM....

Re: Swapping Northstar for LS Engine

buy a fleetwood that has an LT1 already in it (they are identical to the impala SS) and are already rwd. An LS swap on one of these would be easy, but it would be much easier and more cost effective to just mod out the LT1 (they came in corvettes, z28's and trans ams) and there is tons of aftermarket support for it

Re: Swapping Northstar for LS Engine

Originally Posted by N0DIH

The beauty of the 5.3L LS4 is the only difference between the 5.3L and the 6.0L is crankshaft. So you can easily make the LS4 a LQ9 with only a crank, heads and cam change and you are close to 400 hp. And with an aftermarket cam and some porting, it makes for an easy 450-500 hp engine with excellent street manners. You can easily do PCM tuning on the LS engines, but virtually nothing exists for the N* in tuning. So no matter what mods you do, the engine will never run right and always be limited.

Re: Swapping Northstar for LS Engine

So from what I can gather, it hasn't been done nor explored very deep?

My mom and dad have a 97 Deville, if the N* goes, they are going to ditch the car, so if I can get it from them for a decent price, maybe an LS4 swap would be in the picture, then fix up the N*/4T80E and sell it to make up for the cost of the LS44T65E....